1. Field of the Invention
The present invention relates to a resin panel, a sandwich panel in which the resin panel is covered by skin sheets, and relates to a molding technique therefor.
2. Description of the Related Art
Conventionally, sandwich panels have been employed in a wide range of applications, from those in transportation machinery such as automobiles, airplanes, and the like, to those in construction, electrical equipment housings, sports and leisure, and so on. A sandwich panel has a core material of a resin panel covered by skin sheets; in some, only one surface of the core material is covered by skin sheets, while in others, both surfaces of the core material are covered by skin sheets. Sandwich panels in which only one surface of the core material is covered by skin sheets are employed, for example, in applications such as construction, in which it is not necessary for the other surface of the core material to be covered by skin sheets since it is not visible to the user. Sandwich panels in which both surfaces of the core material are covered by skin sheets are also referred to as sandwich panels. A sandwich panel has two skin sheets, and a core material interposed between both of the skin sheets. Specifically, the basic format of a sandwich panel is a stacked structure of one skin sheet, a core material, and another skin sheet.
Sandwich panels of a core material of expanded resin (that is, resin foam) covered by skin sheets have been known (for example, see International Publication Pamphlet No. WO 2010/050242). The core material of this sandwich panel has a plurality of hollows that form voids in the interior, with appropriate setting of the number of hollows and the total opening area, thereby ensuring compressive stiffness.